1. Field of the Invention
The present invention relates to a wind turbine generator tower.
2. Description of Related Art
In general, a wind turbine generator tower is constructed by arranging and connecting a plurality of approximately cylindrical tower sections in their axial direction. This is because it is difficult to carry the wind turbine generator tower in the assembled state, which has a height of several tens of meters, to a construction site. Therefore, the tower sections formed to have portable sizes are carried to the construction site of the wind turbine generator and are connected at the construction site to construct the tower.
Flanges are usually provided at axis-wise end portions of the respective tower sections, and, in a state where the axis-wise end portions of the tower sections face each other, the flanges lying on top of each other are fastened by bolts to connect the tower sections.
However, when the flanges'are provided at the ends of the respective tower sections in this way, the cost required to form the flanges is relatively high due to the high flatness required for the joint surfaces of the flanges, thus increasing the cost required to construct the wind turbine generator tower as well.